1. Field of the Invention
The present invention relates to a light control plate, a surface light source device and a transmissive image display device.
2. Related Background Art
A surface light source device that outputs parallel light having a uniform luminance distribution, as illumination light, is described in, for instance, Japanese Patent Application Laid-open No. 2006-351519. This surface light source device comprises a light-diffuser plate disposed in front of a plurality of light sources that are arranged spaced apart from each other in a lamp box. The light-diffuser plate is provided with a deflection structure having a shape such that incident light from the plurality of light sources that strikes the light-diffuser plate can be deflected and emitted in a forward direction that is a substantially perpendicular direction to the surface of the light-diffuser plate. By passing through the light-diffuser plate, the light outputted from the plurality of light sources can be guided as a result into a forward direction, which is a substantially perpendicular direction to the surface of the light-diffuser plate, while allowing, through diffusion, to output parallel light having a uniform luminance distribution, as illumination light.